SQL Server - Convert date field to UTC

Question

I have recently updated my system to record date/times as UTC as previously they were storing as local time.

I now need to convert all the local stored date/times to

Answer 1

With SQL Server 2016, there is now built-in support for time zones with the AT TIME ZONE statement. You can chain these to do conversions:

SELECT YourOriginalDateTime AT TIME ZONE 'Pacific Standard Time' AT TIME ZONE 'UTC'

Or, this would work as well:

SELECT SWITCHOFFSET(YourOriginalDateTime AT TIME ZONE 'Pacific Standard Time', '+00:00')

Either of these will interpret the input in Pacific time, properly account for whether or not DST is in effect, and then convert to UTC. The result will be a datetimeoffset with a zero offset.

More examples in the CTP announcement.